Multiple serial port controller

1. A serial bus interface circuit, comprising: at least two serial ports; a memory to store a relationship between serial bus addresses and the at least two serial ports; and a controller to control access to the at least two serial ports, wherein the controller is configured to: receive an access request for a serial bus address; determine a first port of the at least two serial ports corresponding to the serial bus address using the relationships stored in the memory; and disable a second serial port of the at least two serial ports to prevent transmission to the second serial port.

2. The serial bus interface circuit of claim 1 , wherein each serial port of the at least two serial ports not corresponding to the serial bus address are to be disabled.

3. The serial bus interface circuit of claim 1 , wherein data is to be transmitted to the first serial port and not the second serial port.

4. The serial bus interface circuit of claim 1 , wherein a port enable signal is to be output to the first serial port.

5. The serial bus interface circuit of claim 1 , wherein the controller is to use the serial bus address from a packet to determine the first port and to disable the second port.

6. The serial bus interface of claim 1 , wherein the controller is to use the serial bus address from a transfer descriptor to determine the first port and to disable the second port.

7. The serial bus interface circuit of claim 3 , wherein the second serial port is to be shut off before the data is to be transmitted.

8. A method of operating a serial bus interface, comprising: providing at least two serial ports; storing a relationship between serial bus addresses and the at least two serial ports; receiving an access request for a serial bus address; determining a first port of the at least two serial ports corresponding to the serial bus address based on the stored relationships; and disabling a second serial port of the at least two serial ports to prevent transmission to the second serial port.

9. The method of claim 8 , further including disabling each serial port of the at least two serial ports not corresponding to the serial bus address.

10. The method of claim 8 , further including transmitting data to the first serial port and not the second serial port.

11. The method of claim 10 , further including shutting off the second serial port before the data is transmitted.

12. The method of claim 8 , further including outputting a port enable signal is to the first serial port.

13. An electronic system, comprising: a processor; memory coupled to the processor; and a universal serial bus (USB) interface circuit including: at least two USB ports; a local memory to store a relationship between serial bus addresses and the at least two USB ports; and a controller to control access to the at least two USB ports, wherein the controller is configured to: receive an access request for a serial bus address; determine a first USB port of the at least two USB ports corresponding to the serial bus address using the relationships stored in the local memory; and disable a second USB port of the at least two USB ports to prevent transmission to the second USB port.

14. The electronic system of claim 13 , wherein each USB port of the at least two USB ports not corresponding to the serial bus address are to be disabled.

15. The electronic system of claim 13 , wherein data is to be transmitted to the first USB port and not the second USB port.

16. The electronic system of claim 13 , wherein a port enable signal is to be output to the first USB port.

17. The electronic system of claim 15 , wherein the second USB port is to be shut off before the data is to be transmitted.

18. The serial bus interface of claim 5 , wherein the packet is to be received from a port upstream to the at least two serial ports.